Integrated electrical connector

ABSTRACT

An electrical connector is formed from a sheet of electrically conductive material that lies in between the two layers of nonconducting material that comprise the casing of an electrical chip. The connector is electrically connected to an electrical element embedded within the chip. An opening in the sheet is concentrically aligned with a pair of larger holes respectively bored through the nonconducting layers. The opening is also smaller than the diameter of an electrically conductive contact pin. However, the sheet is composed flexible material so that the opening adapts to the diameter of the pin when the pin is inserted therethrough. The periphery of the opening applies force to the sides of the pin when the pin is inserted, and thus holds the pin within the opening and in contact with the sheet, by friction. The pin can be withdrawn from the connector by applying sufficient axial force.

[0001] The United States Government has rights in this invention pursuant to Contract No. W-7405-ENG-48 between the United States Department of Energy and the University of California for the operation of Lawrence Livermore National Laboratory.

BACKGROUND OF THE INVENTION

[0002] The invention relates to an electrical connector and, more particularly, a conducting sheet integrated into an electrical chip and having an opening for making electrical contact with a contact pin inserted therethrough and for holding the pin within the opening.

[0003] Micro electrical apparatus are used where a very small size is required, such as in electronic chips and micro fluidic devices. However, their minute dimensions make it very difficult to electrically connect them to related circuitry, other components or power sources. Such connections are typically made using conductive epoxy or solder, both of which are very difficult to microscopically apply with precision. The inaccuracy and error inherent in applying epoxy and solder to microscopic areas can result in short circuits or unintended connections. Furthermore, the foregoing connections are rigid and fixed, making the repair or replacement of components time consuming and difficult.

[0004] One approach to this problem is to fabricate an electrical interface that is compatible with the two electrical elements being connected. However, the interface is typically larger than the micro device being connected, and thus compromises the advantage in size otherwise gained by using such a device.

[0005] As may be seen from the foregoing, there presently exists a need in the art for an electrical connector which is minute and provides for easy connection and disconnection, while not being prone to causing a short circuit or other unintended electrical connection while being connected or disconnected. The present invention fulfills this need in the art.

SUMMARY OF THE INVENTION

[0006] Briefly, the present invention is an electrical connector that is an integral part of an electrical chip and is electrically connected to one or more electrical elements embedded therein. The connector is formed from a sheet of electrically conductive material that lies in between and is held in place by nonconducting layers of material that form the casing of the chip. The connector provides an electrical connection between the chip and external circuitry, electrical components, or a power source; reliably maintains the connection; and allows the chip to be quickly disconnected when desired.

[0007] An opening in the sheet is concentrically aligned with a pair of larger holes respectively bored through the nonconducting layers composing the chip casing. The opening and holes are sized to accept a conductive contact pin to be inserted therethrough when the chip is to be electrically connected to the device or component that is electrically connected to or a part of the contact pin. The minimum breadth of the opening is smaller than the diameter of the contact pin and the sheet is composed flexible material so that the opening adapts to the diameter of the contact pin when the pin is inserted therethrough. Moreover, the periphery of the opening applies a normal force to the sides of the contact pin when the pin is inserted, and thus holds the pin within the opening by friction. This maintains the electrical connection.

[0008] Metal lines buried in the chip connect the connector to an electrical element embedded within the chip. The pin can be withdrawn from the connector by applying sufficient axial force. The chip can thus be easily disconnected from the external components or elements electrically connected to the contact pin.

[0009] Where a chip contains a plurality of electrical elements, a connector for each of the elements is formed from the sheet. The connectors are electrically isolated from each other, and each is electrically connected, respectively, to an electrical element embedded in the chip. Each of the openings is respectively aligned with a pair of holes in the layers comprising the chip casing. The contact pins are attached together by a harness so that all of the pins can be simultaneously inserted, or disconnected, in one step. The harness is held in place by the friction applied by the connectors against the respective contact pins.

[0010] The electrical connector of the invention obviates the need for using epoxy, solder, or a bulky electrical interface to electrically connect a chip with other electrical components or circuitry, and provides for easy disconnection. As the chip is of times an integral part of a micro electromechanical or microfluidic system, the connector of the present invention allows standard hardware to be used to mechanically connect the system that includes the chip to other devices at the same time the electrical connection is being made. The present invention thus allows the use of standard connecting hardware originally designed for semiconductor integrated circuits such as dual inline sockets and pin grid arrays, as well as connecting hardware designed to make fluid or fiber optic connections with the chip.

[0011] These and other features, aspects and advantages of the present invention will become better understood with reference to the following drawings, description and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012]FIG. 1 is a top view of the electrical connector of the present invention embedded within an electrical chip.

[0013]FIG. 2 is a side sectional view of the electrical connector of the present invention, taken along line 2-2 of FIG. 1.

[0014]FIG. 3 is the side sectional view of the electrical connector of the present invention shown in FIG. 3, with a contact pin inserted therethrough.

[0015]FIG. 4 is a top view of a chip including a plurality of the electrical connectors of the present invention. Part of the top layer is cut away to show the underlying connectors.

DETAILED DESCRIPTION OF THE INVENTION

[0016] Turning to the drawings, FIG. 1 shows a top view of connector 11 of the present invention located within chip 13. As shown in the side section view provided by FIG. 2, chip 13 is comprised of top layer 15 and bottom layer 17. Both layers are composed of ceramic, nonconductive material. Sheet 18 is sandwiched in between top layer 15 and bottom layer 17, and is composed of flexible conductive material, such as beryllium copper. To give an idea of scale, chip 13 is 0.5 to 2.0 mm thick, and sheet 18 is 0.05 to 0.2 mm thick. Connector 11 is formed from sheet 18. Sheet 18, and thus connector 11, is electrically connected to an electrical element (not shown) embedded within chip 13 by means of wire 19.

[0017] Connector 11 includes centripetal fingers 20, 21, 23 and 25 that converge to form opening 27. Opening 27 is a polygon having a maximum breadth and a minimum breadth. Top layer 15 includes hole 29, and bottom layer 17 includes hole 31. Hole 29 has a diameter greater than the maximum breadth of opening 27, and hole 31 has a diameter greater than that of hole 29. Opening 27, hole 29, and hole 31 are concentric, and share axial centerline 33.

[0018] Alternatively, opening 27 may be a shape other than a polygon, e.g., a circle, an ellipse or a slit. If a circle, the diameter of opening 27 would be less than the diameter hole 29.

[0019] Cylindrical contact pin 35 is electrically conductive, and is connected to an electrical device (not shown) external to chip 13. Pin 35 has a diameter greater than the original, unstressed minimum breadth of opening 27, and less than that of hole 29. As illustrated in FIG. 3, when pin 35 is inserted through opening 27, it stresses opening 27 by forcing the centrifugal bending of fingers 20, 21, 23 and 25, thereby increasing the minimum breadth of opening 27 until it equals the diameter of pin 35. This causes fingers 20, 21, 23 and 25 to contact and exert a normal force against the side of pin 35.

[0020] When an axial force is applied to pin 35 in a direction that would withdraw it from opening 27, the normal force generates a frictional force opposing such a withdrawal force. This frictional force tends to hold pin within opening 27 and restrain it from being withdrawn. At the same time, the contact between fingers 20, 21, 23 and 25, and pin 27 establishes an electrical connection between connector 11 and pin 27, and thus between the electrical element in chip 13 connected to connector 11 and the electrical device connected to pin 35.

[0021] As shown in the top view provided by FIG. 4, chip 13 may contain a plurality of connectors 11, with each connector 11 being connected to an electrical element embedded within chip 13. For example, one of connectors 11 is shown connected to element 37. This configuration allows the simultaneous connection of a number of elements within chip 13 to a plurality of pins 35, and hence to a plurality of electrical devices or components external to chip 13, respectively. More particularly, pins 35 are attached to a rigid harness (not shown). Pins 35 are spatially arranged so that each pin 35 will be simultaneously inserted into a respective opening 27 when the harness is positioned adjacent to or abutting chip 13. In addition to preventing the translation of pins 35 with respect to chip 13 and maintaining the electrical connection of pins 35 and the elements embedded within chip 13, this configuration prevents the rotation of pins 35 and the harness with respect to chip 13.

[0022] It is to be understood, of course, that the foregoing description relates to several embodiments of the invention and that modifications may be made without departing from the sprit and scope of the invention as set forth in the following claims. 

What is claimed is:
 1. A connector for electrically connecting a chip and a conductive contact pin, comprising: the chip being comprised of a nonconducting top layer, a nonconducting bottom layer and a conductive sheet situated in between the top layer and the bottom layer; the chip including a passageway at least partially therethrough; and the passageway including means for holding the pin in contact with the sheet and for restraining the pin from translating with respect to the chip.
 2. The electrical connector as defined in claim 1 wherein: the holding means includes means for applying a frictional force against the pin, whereby a withdrawal of the pin from the passageway is resisted.
 3. The electrical connector as defined in claim 2 wherein: the pin has a lateral side; and the holding means includes means for applying a normal force against the side, whereby the frictional force is generated when a force is applied to the pin in a direction that would, in the absence of the frictional force, withdraw the pin from the passageway.
 4. The electrical connector as defined in claim 2 wherein: the passageway includes an opening through the sheet; and the opening has a breadth that increases when the pin is inserted therethrough.
 5. The electrical connector as defined in claim 4 wherein: the passageway is further comprised of a top hole through the top layer, and a bottom hole through the bottom layer; and the top hole, the bottom hole and the opening are aligned.
 6. The electrical connector as defined in claim 5 wherein: the opening, when unstressed, has an unstressed minimum breadth; the pin is cylindrical and has a diameter; the unstressed minimum breadth is smaller than the diameter of the pin; the opening has a periphery; and the sheet is comprised of a flexible material so that the periphery can deflect into the bottom hole when the pin is inserted into the opening.
 7. The electrical connector as defined in claim 5 wherein the sheet is composed of a flexible material so that the breadth varies responsive to the contact pin being inserted therethrough.
 8. The electrical connector as defined in claim 7 wherein: the breadth varies between an unstressed minimum breath and a stressed breath, with the stressed breath being greater than the unstressed minimum breath; the contact pin has a diameter greater that the unstressed minimum breadth; and the breadth increases to the stressed breadth in response to the contact pin being inserted into the opening.
 9. The electrical connector as defined in claim 8 wherein the opening is formed by a plurality of fingers extending centripetally from a section of the sheet that circumscribes the opening.
 10. The electrical connector as defined in claim 8 wherein: the top hole has a top hole diameter and the bottom hole has a bottom hole diameter; and the top hole diameter is smaller that the bottom hole diameter.
 11. The electrical connector as defined in claim 1 comprising means for preventing rotation of the pin with respect to the chip.
 12. The electrical connector as defined in claim 1 further comprising: a plurality of passageways through the chip; and a harness including a plurality of the pins spatially arranged so that each of the pins can be simultaneously aligned with one of the passageways, respectively, whereby all of the pins can be simultaneously inserted into passageways, respectively, and the harness is prevented from translating or rotating relative to the chip by the holding means when the contact pins are respectively inserted into the passageways.
 13. The electrical connector as defined in claim 12 wherein: each holding means is electrically isolated from the other holding means and is electrically connected to a respective chip element, whereby each chip element is electrically connected to a respective contact pin when the contact pins are respectively inserted into the passageways.
 14. The electrical connector as defined in claim 1 wherein: the chip is from 0.5 to 2.0 millimeters thick; and the sheet is from 0.05 to 0.2 millimeters thick.
 15. A connector for electrically connecting a chip and a conductive contact pin, comprising: the chip including a nonconducting top layer, a nonconducting bottom layer, and an electrical element; a conductive sheet situated in between the top layer and the bottom layer, and being electrically connected to the element; the top layer having a top hole therethrough, and the bottom layer having a bottom hole therethrough, with the top hole and the bottom hole being in alignment and comprising an aligned hole pair; the sheet having an opening aligned with the aligned hole pair; and the opening including means for holding the pin in contact with the sheet when the pin is inserted into the opening, whereby the pin is prevented from translating with respect to the chip and an electrical connection between the pin and the element is established and maintained.
 16. The electrical connector as defined in claim 15 wherein: the chip is from 0.5 to 2.0 millimeters thick; and the sheet is from 0.05 to 0.2 millimeters thick.
 17. The electrical connector as defined in claim 15 comprising: a plurality of the aligned hole pairs and openings; and a harness including a plurality of the pins spatially arranged so that each of the contact pins can be simultaneously aligned with one of the aligned hole pairs and openings, whereby each of the contact pins can be simultaneously inserted into one of the aligned hole pairs and openings, respectively, and the harness is held stationary relative to the chip by the holding means when the pins are inserted.
 18. A method for electrically connecting a chip and a conductive contact pin, comprising mechanically holding the pin in a passageway in the chip while establishing and maintaining an electrical connection between the pin and an electrical element embedded in the chip.
 19. The connecting method recited in claim 18 wherein mechanically holding the contact pin in the passageway is carried out by generating a frictional force acting on the pin.
 20. The connecting method recited in claim 19 wherein generating the frictional force is carried out by applying a normal force against the pin.
 21. The connecting method recited in claim 20 additionally providing the chip with a flexible conductive sheet electrically connected to the electrical element and having an opening aligned with the passageway, wherein the electrical connection is maintained and the normal force is applied by inserting the pin into the opening and deforming the opening.
 22. The connecting method recited in claim 21 comprising: providing a plurality of passageways and openings; and attaching a plurality of the pins to a rigid harness and spatially arranging the pins so that each of the pins can be simultaneously inserted into one of the passageways and the opening aligned therewith. 